Kind of depends on the nature of the development...Having spent the past 2 weeks developing for Magento... Development for WordPress is a breeze!! lol
WordPress is brilliant if the plugin is there for what you need (and most times there is one!). But if what you need is quite specific and requires custom code, it certainly wouldn't be my first choice. I'd go for Ruby, Laravelle or the .Net framework - all of which support an MVC approach.